What is CVE-2021-1255?

CVE-2021-1255 is a medium-severity vulnerability in Cisco Data Center Network Manager, classified under Incomplete List of Disallowed Inputs. CVSS score: 4.6/10. Published 2021-01-20.

How severe is CVE-2021-1255?

Medium severity. CVSS v3 base score is 4.6 out of 10.

Vulnerability in Cisco Data Center Network Manager

CVE-2021-1255

Multiple vulnerabilities in the REST API endpoint of Cisco Data Center Network Manager (DCNM) could allow an authenticated, remote attacker to view, modify, and delete data without proper authorization. For more information about these vulnerabilities, see the Details section of this advisory.

Published 2021-01-20 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.6 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.007 (49.9th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 50th percentile — 49.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-184 — Incomplete List of Disallowed Inputs

References

tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-dcnm-api… (vendor-advisory, Vendor Advisory)

Frequently asked questions

What is CVE-2021-1255?: CVE-2021-1255 is a medium-severity vulnerability in Cisco Data Center Network Manager, classified under Incomplete List of Disallowed Inputs. CVSS score: 4.6/10. Published 2021-01-20.
How severe is CVE-2021-1255?: Medium severity. CVSS v3 base score is 4.6 out of 10.